Cutter-head for mining-machines.



J C. HIRST. CUTTER HEAD FOR MINI'NG MACHINES.

APPLICATION FILED 00117, 191o.-

990,554,, Patented Apr. 25, 1911.

c/ /avz 6%762 W7, 6410mm llNlT A CUTTER-HEAD FOR MINING-MACHINES.

Specification of Letters Patent.

Patented Apr. 25, 1911.

Application filed October 17, 1910. Serial No. 587,542.

To all whom it may concern:

Be it known that 1, JOHN C. Hrnsr, citizen of the United States, residing at Reynoldsville, in the county of Jefferson and State of Pennsylvania, have invented certain new and useful Improvements in Cutter-Heads for Miuing-h lachines, of which the following is a specification.

This invention comprehends certain new and useful improvements in machines for mining coal, and the invention has for its primary object an improved construction of cutter head which will be effective in operation to cut into the coal with a minimum of dust or slack, which will be comparatively easy to manufacture and of low cost, which will cut the coal rapidly and make much coarser cuttings than has heretofore been possible, and which will be so arranged that the parts which comprise the cutter head may be easily assembled and securely main tained in proper relative position without danger of coming apart, and without the necessity of set screws to hold the parts in place. And the invention also has for its ob ject an improved cutter head of this character which embodies an end bit so arranged that it will serve to hold all of the cutting disks in assembled relation on the rotary cutter shaft, said end bit turning against the thread when cutting coal and therefore avoiding all liabilty of its becoming loose.

lVith these and other objects in view as will more fully appear as the description proceeds, the invention consists in certain constructions, arrangements and combina tions of the parts that I shall hereinafter fully describe and claim.

For a full understanding of the invention, reference is to be had to the following description and accompanying drawings, in which:

Figure 1 is a longitudinal sectional View of a cutter head constructed in accordance with my invention, the end bit being shown in elevation; Fig. 2 is a detail side view of the end bit; Fig. 3 is a detail view of one of the cutting disks; Fig. 4 is a similar view of an other form of cutting disk; and, Fig. 5 illustrates a set of still another form of disks.

Corresponding and like parts are referred to in the following description and indicated in all the views of the drawings by the same reference characters.

Referring to the drawing, the numeral 1 designates the main rotary driving shaft of a rotary coal mining machine, said shaft being bored and tapped at its forward end, as indicated at 2, so as to receive the threaded rear end 3 of a cutter head spindle 4:, said spindle being formed intermediate of its ends and at the juncture of the main portion thereof with the threaded portion of the spindle, with a butt collar or flange 5, one face of which forms a shoulder designed to abut against the forward end of the main shaft 1, while the opposite face forms a shoulder for the next adjacent cutting disk. It is to be understood that the main disk supporting portion of the spindle 4: may be square or of other non-circular cross section, or it may be round and formed with a groove or spline to co-act with splines or grooves formed in the cutting disks which the spindle is designed to support.

In that embodiment of the invention illustrated in Figs. 1 and 3, the disks are designated 6 and are four in number, although it is to be understood that any desired inunber of disks may be arranged preferably at equal distances apart on the spindle 4. The disks 6 are formed with square openings 7 by which they are adapted to he slipped over the square spindle 4:, one of said disks abutting against the forward face or shoulder of the collar 5, and the other disks being held in spaced relation to the rearmost disk by means of spacing thimbles 8 adapted to be slipped over the spindle, as clearly illustrated in the drawing. Preferably, the disks decrease in size regularly from the rearmost to the foremost, so as to give the cutter head a forwardly tapering formation. It is also preferred that the foremost disk 6 of the set have its cutting edges forwardly off-set, as indicated at 9, so as to co-act to a certain extent with the end bit 10 in cutting into the coal. The end bit 10 may be of any desired shape, although it is preferably formed with oppositely disposed beveled cutting edges 11, and it is provided with a threaded shank 12 adapted to be worked into a threaded socket 13 formed in the foremost end of the spindle 4, a washer 14 being preferably interposed between the end bit and the foremost cutting disk 6 and bearing against the latter so as to distribute the pressure, whereby the end bit holds all of the cutting disks in place.

From the foregoing description in connection with the accompanying drawing, it will be manifest that my improved cutter arm head can be manufactured at a relatively low cost, the parts thereof readily assembled and the parts securely held in position by tightening theend bit 10 in the socket 13, said end bit by itself holding all of the parts against displacement and without the necessity of using loose picks, set screws or similar accessories. In assembling the parts, the disks 6 are slipped over the spindle 4 one after the other with the spacing thimbles 8 and the end bit 10 finally applied to hold the parts in assembled relation to each other. As the end bit 10 turns against the thread when cutting coal, it can not possibly get loose. Should any of the parts become broken, it is obvious that they may be easily replaced, the parts being easily slipped over the spindle 4 after the end bit 10 has been detached.

It is to be understood that my invention is not limited to cutting disks having any number of teeth, nor to any particular construction or arrangement of parts whereby the disks are held from independent rotation on the spindle 4. For instance, as illustrated in Fig. 4:, the disks, there designated 7 may have three teeth instead of four, and as illustrated in Fig. 5, the disks there designated 7" may have two teeth. This last named View also shows that the disks may be provided with round openings to receive a round supporting spindle and grooves 15 to receive a spline on said spindle. This view also illustrates that in the preferred arrangement of this modification or embodiment of the invention, the grooves 15 are set alternatively relative to the cutting teeth of the disks, whereby the teeth of one disk will be held in right angular relation to the teeth of the two adjacent disks.

Having thus described the invention, what is claimed as new is:

l. A cutter head, comprising a spindle, cutting disks adapted to slip on said spindle, means for spacing the disks on the spindle, an end bit secured to the forward end of the spindle, and a washer interposed between the end bit and the outermost disk of the set and engaging the latter, for the purpose specified.

2. A cutter head, comprising a spindle, a series of cutting disks carried by said spindle and mounted thereon in spaced re lation to each other, the disks being provided with cutting teeth and decreasing in size gradually from the rearmost disk toward the foremost disk, the foremost disk being formed with forwardly off-set teeth.

3. A cutter head, comprising a spindle, a series of cutting disks carried by said spindle and mounted thereon in spaced relation to each other, the disks being provided with cutting teeth and decreasing in size gradually from the rearmost disk toward the foremost disk, the foremost disk being formed with forwardly off-set teeth, and an end bit secured to the spindle at the foremost end thereof, the teeth of said foremost disk projecting partially around the end bit.

In testimony whereof, I afiix my signature in presence of two witnesses.

JOHN o. nrasr. [15. s.]

\Vitnesses:

W. R. CALVERLEY, T. A. FURNIss.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, I). G. 

